Seasonal Variation of the Composition and Density of Phytoplankton in Inner Ambon Bay

F S Pello,A Damar,E M Adiwilaga,N V Huliselan

doi:10.5296/ast.v2i1.4808

Abstract

Seasonal variation of conditions in Ambon Bay affected the existence of phytoplankton organisms. These organisms are the dominant pelagic primary producers that convert inorganic substances into organic compounds through the photosynthetic processes. This study aims to determine the composition, density, and distribution of phytoplankton in relation to the characteristics of the waters. Phytoplankton sampling was conducted vertically in the euphotic zone by using a plankton net KITHARA every month from June 2011 to May 2012. This study found 4 classes of phytoplankton which consist of Bacillariophyceae (38 genera), Dinophyceae (13 genera), Cyanophyceae (1 genus), and Chrysophyceae (2 genera). Genus Trichodesmium , Cyanophyceae class dominated waters in East Season, Transition Season II, West Season and Transition Season I. ANOVA test of the abundance of phytoplankton obtained significant differences in the distribution of the both temporal and spatial, the correlation of the physical and chemical characteristics of the waters with an abundance of phytoplankton showed that East Season dominated by Gonyaulax (Dinophyceae) and Bellerochea (Diatom) which is influenced by phosphate, silica, ammonia, turbidity, pH and DIN:DIP. Transition Season I and West Season dominated by Triceratium, Skeletonema, Bacillaria, Planktoniella, Ditylum, Diploneis and Prorocentrum are affected by temperature, salinity, nitrite, ration of dissolved inorganic nitrogen to dissolved silicon, secchidepth and euphotic zone.

Highlights

Ambon bay waters consist of Inner Ambon Bay and Outer Ambon Bay which are bounded by shallow waters
Transition Season I and West Season dominated by Triceratium, Skeletonema, Bacillaria, Planktoniella, Ditylum, DiploneisandProrocentrum are affected by temperature, salinity, nitrite, ration of dissolved inorganic nitrogen to dissolved silicon, secchidepth and euphotic zone
(inter-season), the average of phytoplankton abundance in waters is high in Transition Season II (Figure 2) (ANOVA, P

Summary

Introduction

Ambon bay waters consist of Inner Ambon Bay and Outer Ambon Bay which are bounded by shallow waters. These waters confine the water circulation in Inner Ambon Bay (Anderson & Sapulete, 1981). Inner Ambon Bay gets nutrient input from lands through many rivers and Outer Ambon Bay. According to Tuhumuryet al. (2007), in consequence of settlement construction on upper land, the sea gets its effect that in the heavy rainy season, sea water color turns to brownish. Population growth in the seashore, especially in estuary area highly plays the role to the occurrence of eutrophication which can be related to the dangerous algae blooming and waters quality deterioration problem (Domingues et al, 2010), such as the disaster of dangerous algae blooming from the species of Pyrodiniumbahamense in Inner Ambon Bay in 1993 which takes human casualties (Wiadnyana, 1996), Alexandrium affine in 1997 (Wagey, 2001), Pyrodinum spp and Alexandrium spp (Tuhepaly, 2012)

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